Tunnel-kiln



A. C. SHEPARD.

TUNNEL KILN APPLICATION FILED JAN. 26. 1920.

Patented Jan. 25, 1921.

2 SHEETS-SHEET l.

Was

INVENTOR BY his ATTORNEY 8 MM A. C. SHEPARD.

TUNNEL KILN.

APPLICATION FILED um. 26. 1920.

1,366,424. Patented Jan. 25, 1921.

2 SHEETS-SHEET 2 UNITED STATES PATENT OFFICE.

ARTHUR C. SHEPARD, 0F SEBBING, OHIO, ASSIGI IOR TO AMERICAN DRESSLERTUNNEL KILNS, INQ, OF NEW YORK. N. Y.. A CORPORATION OF NEW YORK.

TUNNEL-KILN.

Specification of Letters Patent.

Patented J an. 25, 1921.

To all whom it may concern:

Be it known that I A-n'rnun C. SHEPARD, a citizen of the United States,and a resident of Behring, in the county of Mnhoning and State of Ohio,have invented certain new and useful Improvements in Tunnel-Kilns, ofwhich the following is a specification.

My present invention relates to tunnel kilns in which a high temperaturezone is maintained in the kilns at adistance from the head or entranceend of the kiln, and in whml the portion of the kiln between the higheiu wrnturc zone and the entrance end forum it heating up zone throughwhich the temperature varies more or less gradually fI'Ol'l'i one end tothe other. in such a kiln as the goods are moved slowly through the kilnfrom its entrance end to and through the high temperature zone, thegoods are gradually brought up to the high temperature prevailing in thehigh temperature zone. I

The object of the present invention is to provide simple and effectivemeans whereby the temperature graduation in the heating up zone of thekiln is controlled, and my in veniion preferably comprises means whereby the temperature in the heating up zone of the kiln may be adjusted tomeet different operating conditions.

Mv present invention was primarily devised as improvement on thewell-known llressler tunnel kiln in wl'iich the high temperature zone ofthe kiln is heated by the combustion of gas in combustion chamberslocated within the kiln at the high temperature zone thereof, andinwhich products of combustion are withdrawn from the combustion chambersproper through conduit extensions thereof passing through the heating upzone of 'thekiln to a point adjacent the duits are connected to somedraft creating device suchas an exhzv' t fan or stack. In this type ofkiln the heat remaining in the products of combustion leavingthe'combustion chamber proper is to a lar e ektent radiated from thewnllsof the con uits conmeeting the combustion chambers to the draftcreatin device, and the heat thus radiated is adsorbed by the oodsassing through the heati upzone o the ki 11. In this type of kiln tereis often a tendency for the mouth 'of the oven to be too hot, so

head end of the kiln where these com.

that the cold goods will be raised too rapidly in temperature onentering it. To avoid this too rapid heuting of the goods veryundesirable with certain classes of goods, it has been the practicetoninke the heating up zone longer than would be otherwise necessury toretard the rapid heating up of the goods or to place a long ante chamberin front of the kiln chamber proper, und :1 specific object of thepresent invention is to provide Simple and effective menus whereby theslow and gradual hunting up of the goods may be obtained with a heatingup zone of shorter length than has heretofore been employed Toaccomplish this 1 pro vide simple and effective means whereby a portiononly of the gaseous products of con bustion are utilized in treating thegoods in the heating up zone of the kiln.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, and the advantages possessed by it reference should be had tothe accompanying drawings and descriptive mutter in which i haveillustratml and described a preferred embodiment of my invention.

()f the drawings:

Figure 1 is a plan with the kiln wall in section of a. portion 01'' atunnel kiln pro vided with my present invention;

Fig. 2 is an elevation in sci-lion on the line 22 of Fig. 1;

Fig. 3 is a section on the broken line 33 of. Fig. 1;

Fig. 4 is a partial section on the line 4-4 of Fig. 1;

Fig. 5 is a view taken similarly to Fig. 1 illustrating a modification;and

Fig 6 is a section on the line 6-6 of fn the drawings l have illustratedthe a plication of my invention to a tunnel kin of the wellknownDressler type. In the kiln shown, A represents the kiln chamber proper,and B the ante chamber at the entrance or head end of the kiln, Truckrails C are provided at the bottom of the chamber for the goods carryingcars N, and benches D are provided at the sides of the track on whichare mounted the combustion chumbers E. These benches also serve toprotect adjacent the goods oorrying ca'rs and-the truck upon which theyrun from the high "temperatures prevailing above the benches.

Each of the two combustion cluimbers E locatedone at each side of thekiln is formed as shown of sections built up out of hollow tile as isusually the custom in Dressler kilns. The end of each combustion cham'ber "E adjacent the entrance end of the kiln 1s connected to a junctionbox F ordinarily formed of cast iron. and provided with a -flange F atone sideprojecting into the end of the combustion chamber. To theopposite side of each junction box F are connected the ends ofa seriesof pipes G usually formed of iron. These pi es receive products ofcombustion from t e corresponding combustion chamber E throu l1 thehollow interior ofthe junction box i. At the entrance end of the kiln,the roup of pipes G are connected into a hoe er or expansion box H.Preferably each junction box F is cemented to the correspondingcombustionchamber and like the latter rests on sand or the likeinterposed between it and the bench D so that it can move longitudinallyof the kiln on the supporting bench D as the relative dimensions of thearts change with variations rn temperature.

referably also each header His anchored to the bench D on which it restsand stuff ing box connections which may be packed with asbestos packingare provided between the tubes G and the'headers H.

Each header H is formed with an aperture in its underside whichregisters with a vertical channel I formed in the corresponding bench D.Each channel I is connected at its lower end with a conduit or channel Ileadin to a suitable device, such as the stack J, or creating thenecessary draft to draw of! the roducts of combustion. Each junction boxis also formed with an aper ture F in itsunderside which communicateswith the u per end of a vertical passage K formed n the correspondinlgbench D. The apentures F and assages are so proportioned and arrangedthat ample communication will not be interfered with as the parts expandand contract. Longitudi nally disposed in each bench isa conduit drchannel which communicates at one end with the corresponding verticalchannel K i and at itSOfIPOS ItB en'd'with the correspond ing verticachannel I. Each chaiinel L thusservs as a bypass about the tubes G throuh which products of combustion may pass roin the correspondingcombustion chamber to the outlet conduit 1'. To re ulate the. relativeamounts of products at combustion passing through each group of pipes Gand through the corresp'ondin byass channehL, I em 10y dampers Nf and bywhich the vertical passages K ari d I respectively may be throttledmore'or 'ess.

"which are the comespondin ha nel LA l? 6 As shown, the dnmper'Mcomprises a body of refractory material which is mounted to slide inaguideway D formed in the masonry work of the bench and extending intothe latter from the adjacent outer wall of the' kiln. Each damper M isprovided with an operating handle or extension 12: extending to theexterior of the kiln. To facilitate inspection, adjustment and repair, atunnel -D is shown as formed beneath the guide wady D and is normallyclosed at its outer en .by a removable door D The dampers M may beconstructed and arranged as are the dampers M and are each shown as provided with an operating handle 12:. Advantageously the channel L isformed of tubular tile section embedded in the concrete which forms thecore or body portion of the benches D. Preferably these tile sectionsare slit longitudinally as indicated at L. These slits and the jointsbetween the adjacent sections of the tile eliminate expam siondiiiiculties which would be experienced if such joints were notprovided.

With the construction illustrated in Figs. 1 to 4 the thermal conditionsin the heating up zone ofthe kiln depend upon the setting of the dampersM and M and the consequent portion of the products of combustion leavingeach combustion chamber passed through the corresponding group of tubesG. located in the heating up zone of the kiln. lay charging thesettingof the dampers and thcratio between the portion of the roducts ofcombustion passing through eac group of tubes G and the remainder of theproducts of combustion assing through the corres 0nding channel L may bevaried an the thermal conditions in the heating up acne correspondin ly.varied to suit operating conditlons. it will be understood. of course,

that with the channels L embedded in inasonrv as shown, the thermalconditions in the eating up zone of the kiln are not directly aii'ectedto any appreciable extent by the temperature or ua'ntity of ases passinthrou h the insu ated channe s L.

Int 1e modl ed construction illustrated in Figs. 5 and ,6 the escapeconduit I A lead ing directly to the stack, or other device for Hbeneaththe vertical channels' KA which communicate at their 1.31pm endswith the openings, in the undersi e of v I boxes F and commuiiicatelatter fwith the. longitudinal I benches 1). Each channel which ma beformed likethe chan nelfs jhyd'scribe j; above, communicates at themegawatt the kiln through a vertical til 'with the interior of thelocated directly s igs. 5 and 6, communi cation etweenthe upper end ofeach verexpansi' xor h ader H. Withthe construc i' hown in l llOremoving the products, of combustion, is

tical channel KA and corresponding junction box F is regulated by thedamper M and communication between the lower end of the channel KA andthe outlet conduit IA is regulated by an adjustable damper Communicationbetween the expansion box or header H at the adjacent end of thecorresponding channel LA is regulated by an adjustable damper M.

The arrangement shown in Figs. 5 and 6 differs from that shown in Figs.1 to 4 in that the products of combustion which pass through each roupof tubes G also )asses through the c iannel LA in the bene beneath thetubes. but in this construction as in that first described a I'egulableportion only of the products of combustion passes through the tubes G inthe heating up zone of the kiln, and the remainder of the products ofcombustion pass to the stack or other exhausting device Withoutinfluence on the temperature of the heating up zone of the kiln. In theconstruction shown in Figs. 5 and (3 the b v-pass by means of which aportion of the products of combustion are diverted away from the pipes Gpassing through the heating u i zone is formed by the vertical channelsA.

lVit-h the construction shown in Figs. 5 and (3, the temperaturenormally prevailing in the channels LA will be less than that normallyprevailing in the channels L of akiin chamber of similar capacity anduse constructed in accordance with Figs. l to i. This lowerten'iperature of the masonry embedded conduits is of some advantage,though ordiuaril no diiliculty will arise on account of the temperatureof the gases passing through the conduits L shown in Figs. 1 10 4.

While in accordance with the provisions of the statutes I haveillustrated and describcd the best form of embodiment in my inventionnow known to me, it will be apparent to those skilled in the art thathanges may he made in the form of apparatus disclosed without departingfrom the spirit of my invention-as set forth in the :sppcndcd claims andthat in some cnscs certain features of my invention may be used toadvantage without a correspondii'ig use of other features.

I lavinn now described my invention. what I claim as new and desire tosecure by Letll'lS Patent. is: p I

l. A tunnci kiln with longitudinally extending masonry benches at thesides of a iatl'iway at the bottom of the kiln for goods carrying meansand having mounted on each of said benches an elongated coinbuslionchamber, pipes connected to and forming an extension of said miobustionchant her, and a header to which the ends of the pipes rumor" ironi-ziild combustion chamber are connected. each bench being formed with achannel having uprising end portions which communicate one with theinterior of said header and the other with the interior ot' thecombustion chamber at the opposite ends of said pipes and with an outletfrom said channel for products of combustion, and dampers regulating therelative amounts of products of combustion passing from the combustionchamber to said outlet through said pipes and a portion of said channel.and through the b v-pass about said pipes formed by the remainingportion oi said channel.

2. A tunnel kiln formed with louu'itudh nail extending inasoury benches:u the sides of a pathway at the bottom oi' the kiln for goods carryingmeans and having nionntcil on each of said benches a combustion chamberformed of refractory material, metallic pipes connected to and formingan extension of said combustion chamber. a. junction box connecting saidpipes To said mmbustion chamber and a header to which the ends of thepipes remote from said coinbustion chamber are connected. said iuuctionboxes and headers being formed each with an opening through its bottomwall. each bench being formed with a chanucl having uprising endportions communicating one with the opening in the bottom ol thecorrcspomliug junction box and lln: other with the opening in thecorrespondlug header. and with an outlet for products of combustioncomuuuiicaiin; with said channel. and dampers i'c; 'illaliii, lhc rcla'livc amounts of products of combustion, passiu g from each combustionchamber in the corrcspoiuliu; outlet through said pip s and one portionof said chauncl and through the by-pass about said pipes formed by theremaining portion of said channel.

3. Atunucl kiln with lougril udinally exlcndin, masonry benches at thesides of a pathway at the bottom oi the kiln for goods carrying; meansand having mountcd on each of said bcuchcs an ilflilgjfilli'llcombustion cluunber. pipes couuccicd lo and forming an extension of saidcombustion hamber. and ii header to which the cuds ol' the ipes remotefrom said combustion chamber are connected, cach bench being l'ormcdwith a channel having uprising cud purl ions which communicate one withihe inlci'ioi of said header and ilic other with lien iiililioi of thecombustion chambri at lb og p d u ls o'l. said pipes and with an outletfrom said channel for product of combu tion. and dampers regulating therelative amounts of products of combustion passin from the combustionchamber to said oullct (blowh said pipes and a portion i said channeland through llic bvpass about mu. pll i. formed by tho remaining p-wliwol' s- "l P ll Hill

lilfi channel, the body portion of each of said channels being formed oftubular tile sections jointed together and embedded in con crete.

4. A tunnel kiln with longitudinally extending masonr benches at thesides of a pathway at he bottom of the kiln for goods carrying means andhaving mounted on each of said benches an elongated combustion chamber,ipes connected to and forming an extension of said combustion chamber,and a header to which the ends of the pipes. remote from said combustionchamber are connected. each bench being formed with a channel havinguprising end portions which communiciite one with the interior of saidheader and the other with the interior of the combustion chamber at111;; portion of said channel, t

the opposite ends of said pipes and with an outlet from said channel forproducts of combustion, and dampers regulating the relative amounts ofproducts of combustion passing from the combustion chamber to saidoutlet through said pipes and a portion. of said channel and through thebypass about said pipes formed b{ the remaine body portion of each ofsaid channels being formed of tubular tile sections jointed together andembedded in concrete, each tubular tile section being lon itudinallysplit at one side.

Signed at ittsburgh in the county of Allegheny and State of Pennsylvaniathis 23rd day of January D. 1920.

ARTHUR C. SHEPARD.

